The U.S. Pat. Nos. 3,940,079 and 4,161,297 relate to a yarn feeding device with constant adjustable tension, particularly designed for use in weaving and knitting machines, comprising a fixed hollow body, around which the yarn to be fed is wound into turns by means of an element rotating on the outside of said fixed body to form thereon a yarn reserve, from which the yarn is drawn to be sent to said weaving and knitting machine, passing through the inside of said fixed hollow body. According to the said patents, said feeding device comprises also adjustable brake means, cooperating with said fixed body to brake the yarn at a constant rate downstream of said yarn reserve.
The brake means claimed by the said patents comprise a braking element elastically pressed--with possibility of adjustment--against the edge of the fixed body (preferably formed by a cage) by the framework of the said rotating element. Moreover, the braking element is preferably a ring-shaped body comprising a true and proper braking ring and a set of elastic spokes converging into a hub at the centre of the ring, against said hub an adjustable screw acts which is provided at the centre of said framework, said screw being coaxial to the hollow body of the device and adapted to freely rotate in said hub.
The present invention relates to improved brake means for the feeding device of the type heretofore specified.
Experience has taught that the efficient working of the aforespecified feeding device is very largely due to the efficiency of the brake means of said device, wherefor every possible effort has been dedicated to the improvement thereof. In particular, care has been taken to assure an easy and prompt replacement of the brake means, to adapt them each time to the characteristics of the yarn being fed, and every attention has been devoted to obtaining the utmost smoothness of the braking action.